The coloured hat exam Three students have been put in detention by their evil maths teacher, Mr Chalk.
Do five suffice?
Tiling troubles
Crack a code with Enigma
Plus magazine sudoku
Greater than sudoku!
Graph theory helps answer Sudoku questions
Have a go at this Plus-themed Sudoku variation.
Sudoku around the clock
The Eternity puzzle is back with a $2 million prize